Method of making hollow metallic articles



April 1929. F. c. LANGENBERG 1,710,776

ARTICL Patene Apr. 30, 1929.

FREZDERIGK C. LANGENBERG, O WATERTOWN, MASSAOHUSEITS, ASSIGNOR OIE ONE KALI T TBACY C. DICKSON, OF WATERTOWN,

MASSACHUSEITS.

METHOD OF MAKING E OLLOW METALLC ARTICLES.

Application fi1ed December In my prier Patents No. 1,552,848, dated Sepember 8, 1925 and No. 1,553,824, dated Scptinbcr 1925, I have described methods and apparatus for making metallic articles 5 by subjecting them to an internal fiuid pressure Whiclr expands the article to a 'bo'int beyond the clascic limit of the matcrial employcd, the expansion taking place within a container which limits the extent of expan- O sion ossible. In the apparatus described in said atnt No. 1,553,824 the pressure is appiied to the fiuid by means of a separate apparatus, as for instance, the intensifier shown in an application for Letters Patent of the 5 United States filed by John C. Solberg, J une 12, 1925,.Ser. No. 36,755, and is transmitted to the interior of the hollow article by a suitable conduit. It is reqnently desirable to make hollow mctallic articles by the method described in iny said prier patents without going to the expense 0f making an intensifier for the purpose, or when one is not available. An intensifier is an elaborate and expensive piece of apparatus. Under other circum= i stances it may be desired to malte hollow metallic articles, the elastic limit of which is higher than can be produced by the capacity ofi' the intensifier, thus, for instance, if the intensifier has a capacity of 100,000 pounds,

that is, can produce a pressure on the interior of the hollow article of 100,000 pounds in the square inch, it cannot produce an ar iicle Which Will have an elastic strength caused by enpanding the article under pressures mach greater than 100,000 pounds t0 Lire square incln iniy present invention provides a method by v Which i1olloa*mealiic articles Which have ioeen enpanded beyond the elastic limit of the maierial of which they are composed can. be made without the use of an exterior intensifier; also, articles i1aving an eiasticlimit higher than can loe prodced by the capacity of gi7en intensifier. Speaking generally my presen; invention consiste in fiil1flg i;he

bore o: dis c liinder which is to be expanded With a sniiaoie liquid, ti1en subjecting the liqnid i2o pressure by a rem Which fits the entrance portion 01 the bore and which enpan'ds 1bhe cyiinder to the required amount, and then driliing ont or otherwise removing the metal ai; tne entrance of the bore so that the bore Wili loe oi? uniform bore throughout. It will loe seen that the procednre makes itentirely unnecessary t0 employ any external source of 11, 1925. Serlal No. 74,513.

fluid pressure such; as an intensifier. Another feature of the invention consists in plac- 1ng n the bore a core of relatively incompressible material such as steel, Which reduces the amount of liquid which the bore centaine and thereiorc shortens the stroke of the ram xylnch is necessary to produce a givcn expansion. In practice, a cure which practically fits the boreis employed so that the strokc of the ram is thereby convcniently reduced even t0 a fraction ofan inch.

It will be seen that my invention clin bc conven1ently empl0yed in the manufacture of cylinders for hydraulic presses and that by snpplying a new packing for the ram whirh W111 fit the final size bf the cylinder bore, the press cylinder cari be made by the use of the ram Which is to be employed in the cylinder and ;vithout the manufacture of any special apphances.

The method embodied in my invention is also particularly applicable to the manufactu're ofopen ended cylinders, the material of Which is intended to have an extremely his;h elastic limit.

The invention Will be fully understood from the following description when taken in connection with the accompanying draWings and the novel features thereof will be pointed out and clearly defined in the claims at the close of this specificatiori.

In the drawings: v

Fig. 1 shows the cylinder from Which the final article is to be pro'duccd in place in a restraining jacket. V 7

Fig. 2 shows the bore of the cylinder partly filled with iquid and with a solid ocre and a ram introdnced.

Fig. 3 shows the ram moved inwardly and tne cylinder expanded until the proper amount of distention is obtained.

Fig. 4 shows the cylinder hein rebOred.

Fig. 5 shows the cylinder in its nal form with the unexpanded portions et the top and bottom ont ofl'.

Referring to the drawings:

. In praccing my novel method, I prefcr to take a Cylinder wit-h one end solid. This cylinder indicated et 0 may be constructed of a single piece of me fial or may be built up of a series of concentric members as circumstances may require. The cylinder is then placed in a suitable restraining jacket B, the

interior bore of Which is larger than the exter1or diameter of the cylinder t0 pr0duced therein. The amount of diiererlce between the diameter of the cylinder and the bore of the container will depend upon the amount of expansian which it is desired to give to the cylinder; Next, (see Fig. 2), a ocre M of steel or other relatively non-compressible material is placed in the bore of the cylinder axially concentric therewith and the remaining space is fille'd to the desired level with a suitable fluid, as -for instance, oil N. In practice I make the core M nearly of the size of the bore and have very little space for the expanding fiuid N. A mm D provided with a suitable packing E is then fitted to the bore. A suitable packing for.the purpose is disclosed in the application of John C. Solberg Serial No. 36,7 54, filed June 12, 1925.

' The entire assembl-y is then placed under a suitable press having a press member P and a plat-en L, and the mm D is then forced dOWD-' ward or the cyiinder upward until the desired amount of distention is produced. The expansion is limited by the interior of the jacket B. The distention is shown at F in cxaggerated manner in Fig. 3.

The ram is then remove the core is taken out, and the cylinder taken out of the jacket.

Next, I enlarge the bore so that,it is of uniform diameter throughout its entire length,

elastic limi t than the portion of the cylinder';

walls adjacent the part of the bore which has been expanded, accordingly, if it is. de-

sired to produce an article having walls of a uniform elastic limit or to have an open ended cylinder, I ont off the top and the bottom portions of the cylinder as indicated at H and Iin Fig. 5.

In some case, it is desirable to make the cylinder with the closed end an in this case, the corresponding end of the cylinder is not removed. In other cases the cylinde'r is intended for use with a piston or ram and under these conditions the ram or piston which-is to be used with the completed cylin der can itself be employed in the expansion of the cylinder, it being only necessary to change the packing on the ram to correspond with.the increased diameter due tothe expansion of the cylinder.

W hat I daim is':

1. The method of producing a cylinder of material having a high elastic limit which consists in .forn1ing a cylindrical cavity therein, filling 2), portion of the cavit with fluid, subjecting the fiuid to pressure y a ram fitting the entrnce portion of the cavity thereby expanding the portion of the cylinder surrounding the cavity a predetermined amount and then rendering the bore un1- form throughout by removing the surplus met-a1.

2. The method of producing a cylinder of material having a high elastic limit which consists in forming a cylindrical cavity therein, filling 3. portion of the cavity with fluid, subjecting the fluid to pressure by a'ram fit ting the ntrance portion of the cavity thereby ex anding the portion of the cylinder surroun ing the cavity a predetermined amount, then rendering the bore uniform by removing the surplus metal, and then cutting ofl the ends of the cylinder.

In testimony whereof EREDERICK c. LANGENBERr.

I afiix rny signature. 

